霍林河下游典型洪泛区湿地土壤pH值和土壤含水量分布特征

Distribution of Soil pH Values and Soil Water Contents in Floodplain Wetlands in the Lower Reach of Huolin River

以霍林河下游洪泛区湿地为研究区,采用网格采样法研究了土壤pH值和土壤含水量的时空变化及其相互关系。结果显示,研究区湿地土壤含水量和pH值存在明显的季节性差异,7月份土壤含水量高于9月份土壤,但7月份土壤pH平均值则低于9月份,9月份湿地土壤,尤其是亚表层发生明显碱化。湿地土壤含水量和pH值均呈现出条带状和斑块状的空间分布格局,尤其在9月份的空间变异性较高,且土壤pH值与土壤含水量间存在较显著的负相关关系,即含水量高的区域对应土壤pH值较低。土壤含水量和pH值的回归分析表明当土壤pH值>8.8时,非线性回归更适宜描述研究区土壤含水量和土壤pH值的显著负相关关系。

Spatial distributions of soil pH values and water contents in July and September were investigated using grid sampling method and their correlations were also discussed in Erbaifangzi floodplain wetland in thelower reach of the Huolin River. The results showed that soil water contents and pH values were obviously different in July compared to September. Soil water contents were higher in July than in September, but soil pH values were lower in July compared to September. Soil basified obviously in September, especially the subsurface soil. Both soil water contents and pH values showed spatial distribution patterns of stripes and patches, with higher spatial variability in September. Soil water content and pH value had strong negative correlation, i.e. the patterns with higher soil water contents had lower soil pH values. The regression analysis showed that nonlinear regression was more suitable than linear regression to describe the significant negative correlation between soil water content and pH value when ph〉8.8.